Guard for machinery



-May 5, 192's. 1 1,536,762

. J. BROUGHTON GUARD FOR MACHINERY Filed April 18 1923 4 Sheets-Sheet l May 5, 1925.

' J. BROUGHTON GUARD FOR MACHINERY 4 Sheets-Sheet 2 Filed April 18, 1923 May 5,1925. 1,536,762

J. BROUGHTON GUARD FOR MACHINERY Filed April 18, 1923 4 Sheets-Sheet 3 Fig: 6.

May 5, 1925.

J. BROUGHTON GUARD FOR MACHINERY Filed April 1923 4 Sheets-Sheet 4 mvimogz 4%,! 32 /16 2 v Patented May 5, 1925.

, entree JIQSEBH BZBIOTUZG'HTONy, 01 BIRMINGHAM, ENGLAIN 1);

hcHInERY;

Application filed'ApriLlS, 1923. Serial No; 632,987.

To aZZw/wm it may concerns Be known that-I, J osnrrr BRoUGHToN, a subject of the. King; of Great, Britain, residing at lGreatCharles Street, Birmingham, England, have" invented certain new and useful Improvements in Guards for'Maohinery, of which the followingisa specification; 1 I

'lhisinvention relates to guards for power presses andlother machinery, .thej s 'aichguardsbeingof that type which are adapted to be moved in front of the- Worlt space timing the descent of the plunger or ram of the press or the like, throughth'e medium-t a: lever actuated from the moving part- 0t; the machine.- I I The object ofthe present invention is to, provide vimproved and efficient means for positively actuating the, guard.

According to the invention, the lever which ettects the movement ofthe guard is actuated by a, slidingj member 'oi';plt1n=ge1' operated a moving'part otthe press," the said sliding, member being eoupled to the said, guard-actuating lever-by a' p in and slot COHDGCtlOlL The arrangement 1s1pref= erably, such, as to cause the} guard to move into its operative, position prior tothe press plunger reaching the danger zone. a a

Figure 1" of the accompanying drawings is an elevational View of a press fitted with a, guard' arranged and operated by a sliding member. in accordance with this invention, the said sliding member being actuan-zd from the crank-shaftof the press andbeing shown in its inoperative positionat the top of its stroke, a r

Figure 2is anelevational view of the press illustrating the manner in which the guardis move'd rin frontrot the workingsp ace by the' slidi'ng'membeigthe guide ithin which the latter moves. being; shown in; section;

Figure 3 is avertical sectien throughqthe I sliding member-land its guide when the said sliding member is at .the bottom ofits strok 3 and showing more. clearly the pin and slot connection ,between the. slidiu member and the lever which vactuates the guard- Eigure 4 I'GPI'BSGIUJSI-IQLI similar. sectionto that in Figure 3, but showing the sliding member at the, top of'its stroke.

Eigure 5 shows? a. sliding member having an alternative form ofslot.

Figure 6- shows an, alternative arrangement in which the slidingmember. isoperof a shallow box-like mum forties-,1 I

atedhy the ram oi" the press-instead of the crankshaft.

Figure Tillus-trates afurther modificationin' which the guard iS- causGdFtO more in a vertical 1 direction instead othorizontally.

Figure '8' shows a further arru ngement in- The same reference numerals indicate correspondingpartsineach of the figi-ires.

Referring to Figures lto 4',- tlie-j ua-idol shield '1 is arranged to lie-moved horizontally backwards and forwardsin the --fiont; of? the Working space of the press through the m dium of. a vertically-sliding plate This plate- 2 is arranged to slide withinaguitle formation, openat itsupper and lower ends, the said guide being;

carried by a laterallv=extending bracket 4,

ing rod 9 hinged atits lower end to'the said I plateQ', by a bolt'or other-means, antlihin'ged atits upper end to the pin 8 -s0 as-to be free to turn about thelatter. 'lhus,-owing to the pin 8 being eccentrieally' mounted the rotation of the crank-shaft 6 causes the plate Qtor reciprocate vertically Within the guide The vertical reciprocating. movement at thisplate'Q is eausedto operate the guard 1 through the medium of ahlever and link. This lever comprises a downwardly-inclined which another order of lever'is el-npleyedi long-arm 12. keyed orrigidly fixed at its upper end" to a forwardly-extending horizontalshaft13 (see Figures3fand'4l) mounte ed to turn within a sleeve bearing'll carried by, or integral with, the front-face ottheigui'de the said/shaft 18 constituting the pivot about'ivhich the lever terns; Secured to the opposite end of the shaftli-liistheshort-arm 15 ofth'e lever, this arm. carrying. at its extremity. a rearwardlyprojeeting jpin havin a roller 16 Whicliis arranged:torengage a slot, l'l'fin the sliding plate the. said slot being; preferably of the shape shown, and

f comp rising a vertical portion terminating at its lower end in a short, substantiallyhorizontal heel or extension. The front of the guide 3 is suitably cut away to allow of the roller 16 moving freely within the slot 17. The lower end of the long-arm 12 of the lever is connected to the guard 1 by a substantially horizontal link 18. The guard 1 comprises a plate adapted to be moved backwards and forwards in front of the working-space of the press upon verticallyseparated horizontal guide-bars 15) which pass through sleeves 20 formed at the upper and lower edges of the guard. These horizontal guide-bars 19 are carried at their extremities by vertical members to the bed or frame of the press. Coiled springs 22 are preferably attached to each vertical edge of the guard 1 to prevent injury to the hand of the operator.

The operation of the guard is as follows :VVhen the press plunger or ram 10 is at the top of its stroke the pin 8 upon the end of the crank-shaft 6 is arranged to come atthe top, whilst the roller 16 carried by the short-arm 15 of the lever is arranged so that it then engages with the inner end of the short horizontal extension of the slot 17 as shown in Figure 1 of the drawings. As soon as the press plunger 10 commences its downward stroke the plate 2 is likewise moved downwards causing t e roller 16 upon the short-arm 15 of the lever to be moved from out of engagement with the heel or horizontal extension of the slot 1? so that it engages thevertical portion of the latter. The short arm 15 is thereby moved downwards and laterally and the lever is consequently turned about its fulcrum so that it assumes the position shown in Figure 2, the long-arm 12 of the lever moving in a direction towards the press and forcing the guard 1 across the work-space of the press through the medium of the link 18. The sliding plate 2 starts to move downwards when the press-plunger starts to descend, and owing to the shape of the slot 17 in the plate 2 the guard commences to move into its protecting position, in front of the work-space, as soon as the plunger commences its downward stroke, the movement of the guard into its protecting position being completed shortly after the press plunger ably before it has entered the danger zone. The guard remains in its protective position, as shown in Figure 2, until the pressplunger has nearly completed its succeeding up-stroke, the roller 16 during this time moving idly within the vertical portion of the slot 17. The plate or slide 2 moves upwards with the press plunger so that the roller 16 is thereby moved towards the lower end of the vertical portion of the slot 17,

when, just prior to the plunger completing its up-stroke the roller 1511s caused to engage the short horizontal extension of the 21 attached 1 has started to descend, and prefersaid slot, so that the guard 1 is, at this instant, moved back clear of the workingspaec, leavii'ig the latter unobstructed for the removal or insertion of the work. Shortly after the plunger has again commenced its downward stroke the guard 1 is again fully moved in front of the workspace, as above described.

The connecting-rod 9 for coupling the plate or slide 2 to the pin on the crankshaft is preferably adjustable in length, and comprises a centr portion having externally-screwed e emities which are adapted to be screwed more or less into eye-members for ergaging respectively the pin on the crank-shaft and the pin or bolt which couples the connecting-rod to the plate or slide 2. The length of the connecting rod may thus be varied according to requirements. Nuts may be provided for locking the parts of the connecting-rod after adjustment.

lv here the end of the crank-shaft is of a s "ciently large diameter the pin 8 may be listed directly to the said end, instead of to a collar or boss carried by the latter.

The instant at which the guard 1 is moved into its protecting position in front of the workir g-space may be altered by varying the shape of the slot in the sliding plate 2. Figu'e 5 shows a plate having a slot 17 shaped so as to cause the guard to move across the working-space after the press plunger has reached approximately the middle of its down-st oke, the guard being moved back clear of the working-space when the plunger reaches the middle of the succeeding rip-stroke. The movement of the guard may thus be readily varied to suit different machines by varying the shape of the slot.

Referring to Figure 6 of the drawings, instead of the slidin plate 2 being operated by the crank-shaft, as above described, it may be operated. by the pressure plate or by the ram. For this purpose the upper end of the plate 2 is connected to the outer end of a rigid arm 21 extending horizontally from the pressure plate 10 and connected to the latter by belts or other means. The slide 2 is thus caused to rise and fall with the movement of the pressure plate or ram. The said slide is arranged to work within a. guide 3 and is slotted and adapted to operate the guard 1 by a lever and link, in a similar manner to the above described. The outer end of the arm 21 connecting the slide 2 to the rain or plunger of the press may he screw-threaded and the slide may be adjustcd in the axial direction of the arm by nuts 25.

The guard 1 may be arranged to more in a vertical plane upon guide-rods 19 instead of moving horizontally. Such an arrangement is shown in Figure 7 of the drawings. Theguard 1 is operated by a sliding memher 2 working within a guide 3 in a precisely similar manner, through the medium of a lever attached to the slide 3 by a pin and slot connection, and a link 18. The longarm 12'of the lever is, however, arranged to extend in a substantially horizontal direction when the guard 1 is in its inoperative position, and the press plunger 10 is raised, whilst the link 18 connecting the said arm 12 of the lever to the guard 1 extends down- 'ards as shown in the said figure of the drawings. The short-arm 15 of the lever is upwardly inclined and carries a roller 16 which, when the plunger or ram is raised, engages the-heel or horizontal extension of the slot 17. As the press plunger and the like descends the roller 16 is caused to enter the vertical portion of the slot 17 so that the long-arm' 12 of the lever is consequently moved downwards. The guardl is likewise moved downwards in front of the working space. As the press plunger or ram rises, and when it has nearly reached the end of its upstroke, theroller 16 again enters the horizontal portion of the slot 17- so that the guard is at this instant raised.

Any suitable'form of lever may be employed. Figure 8 of the drawings shows a modified form of lever 12, the upper end of which is cranked horizontally, and 111+ crumed at its extremity at 13, to the guide 3 withinwhieh the slotted plate 2 slides. A

rearwardly extending roller 16 is provided.

near the said pivoted end of the lever which is arranged, to engage the slot 17 in the plate 2. As the latter moves downwards on the downstroke of thepress plunger the lower end of the lever is caused to move in a direction towards the press and so move the guard 1 in front of the working space.

In any of the above arrangements the sliding member 2 may be arranged to work within any suitable form of guide or guides, whilst the said guide or guides maybe attached to any suitable part of the press so as to either come at the side or at the front or rear of the press plunger or ram. Having fully described my invention, what I desire to claim and secure by Letters Patentis v 1. Means for operating guards for machinery comprising fixed guides independent of the guides for the ram of the machine, a slidingmember separate from the am of the machine and working within the said guides, said sliding member having a camshaped slot, means for actuating said sliding member from the crank shaft of the ma chine, and a lever pivoted to a fixed member and carrying a part engaging the slot in the sliding member, the said lever being connected to the guard so as to impart a reciprocating movement thereto.

2. Means for operating guards for machinerycomprising a pin e ccentrically carried by the end of the crank shaft of themachine, a eonnectingrod engaging the said pin, a sliding member operated by the connecting rod and provided with acam-shaped slot, fixed guides engaged by the sliding member, a lever pivoted to a fixed member and carrying a part engaging the slot in the sliding member, and a link attached to the lever, thesaid link being connected to the guard so as to impart a reciprocating movement to same.

In testimony whereof I have hereunto set my hand.

JOSEPH BROUGHTON. 

